St. Augustinegrass (PS-247)

ABSTRACT

A perennial St. Augustinegrass having rapid lateral spread, an outstanding root system, a dark green color, and good gray leafspot resistance. This variety has a good overall turf quality and performs well under sod production conditions.

SUMMARY OF THE VARIETY

This invention relates to a new and distinct St. Augustinegrass. It was derived from a cross between a Texas Common selection (male parent) and a plant selected from open pollinated experimental 6-69-272 (female parent). This genotype first labeled 184 and later PS-247 was propagated vegetatively by stolons to provide planting stock for studying performance and making comparisons to commercially available cultivars.

Genotype PS-247 has a deep purple stigma color and a light purple anther color. It has a moderate leaf blade length and width, and internode length and width when compared to other cultivars. In field tests PS-247 had the longest stolon length, a rapid rate of cover, lowest gray leafspot (Piricularia grisea) incidence readings, and high turf quality ratings. In an aquaculture study PS-247 had a significantly greater number of roots and total root length than other St. Augustinegrass varieties in the test. This information can be used to distinguish PS-247 from other St. Augustine cultivars.

BRIEF DESCRIPTION OF THE ILLUSTRATIONS

FIG. 1 is a photograph of the leaves and stem of a PS-247 St. Augustinegrass plant,

FIG. 2 shows a spike of a PS-247 St. Augustinegrass plant,

FIG. 3 shows mowed turf of PS-247, and

FIG. 4 shows the root development of PS-247 and other St. Augustinegrasses.

DETAILED DESCRIPTION OF THE VARIETY

Genotype PS-247 possesses a Munsell color designation 5.0 GY 5/6^(1/) and is characterized by compressed and branched culms. The leaf blades are moderate in length, averaging 34.6 mm and 49.0 mm for the first expanded leaf and the third leaf, respectively. The leaf blades are moderate in width, averaging 7.8 mm and 8.1 mm for the same leaves. The internode lengths and widths are also moderate in size, averaging 86.2 mm and 2.8 mm, respectively for the first expanded internode; and 97.4 mm and 2.7 mm, respectively for the third internode. This information and comparisons to commercially available cultivars, given in Tables 1 and 2, allow PS-247 to be distinguished from the semi-dwarf Seville and Floratam.

                  TABLE 1                                                          ______________________________________                                         First                                                                          Leaf Blade         Third                                                       Selection-                                                                             Length    Width    Leaf Blade                                          Variety (mm).sup.2                                                                               (mm).sup.3                                                                              Length(mm)                                                                              Width(mm)                                  ______________________________________                                         PS-247  34.6 ± 7.3                                                                            7.8 ± 0.5                                                                            49.0 ± 14.2                                                                          8.1 ± 2.2                               Tex. Com.                                                                              31.2 ± 6.2                                                                            7.8 ± 0.6                                                                            33.8 ± 5.8                                                                           7.6 ± 1.0                               Seville 22.0 ± 3.3                                                                            6.7 ± 0.5                                                                            30.0 ± 7.0                                                                           7.9 ± 0.7                               Raleigh 38.0 ± 8.0                                                                            9.4 ± 1.1                                                                            49.9 ± 22.9                                                                          9.8 ± 1.4                               Floratam                                                                               56.7 ± 13.6                                                                           9.6 ± 1.1                                                                            73.0 ± 25.0                                                                          10.1 ± 1.0                              Floratine                                                                              34.7 ± 8.8                                                                            8.1 ± 0.8                                                                            23.7 ± 3.9                                                                           6.8 ± 1.0                               L.S.D.(.05)                                                                            11.9      1.1      21.5     1.1                                        ______________________________________                                          .sup.2 All plant material grown unclipped in greenhouse.                       .sup.3 Measurements recorded 15 millimeters above leaf collar.           

                  TABLE 2                                                          ______________________________________                                         First                                                                          Internode           Third                                                      Selection-         Width    Internode                                          Variety Length(mm) (mm).sup.4                                                                              Length(mm)                                                                              Width(mm)                                 ______________________________________                                         PS-247  86.2 ± 22.6                                                                            2.8 ± 0.3                                                                            97.4 ± 21.6                                                                          2.7 ± 0.2                              Tex. Com.                                                                              84.3 ± 16.3                                                                            3.1 ± 0.2                                                                            87.8 ± 19.0                                                                          2.9 ± 0.3                              Seville 82.9 ± 17.9                                                                            2.6 ± 0.2                                                                            89.1 ± 10.0                                                                          2.6 ± 0.2                              Raleigh 90.9 ± 15.2                                                                            2.9 ± 0.3                                                                            79.9 ± 21.1                                                                          2.9 ± 0.3                              Floratam                                                                               104.5 ± 20.7                                                                           3.4 ± 0.5                                                                            134.5 ± 4.0                                                                          3.4 ± 2.1                              Floratine                                                                              42.9 ± 34.3                                                                            2.9 ± 0.3                                                                            47.0 ± 25.8                                                                          4.3 ± 2.1                              L.S.D.(.05)                                                                            27.7       0.4      25.0     0.8                                       ______________________________________                                          .sup.4 Internode width is recorded equidistant between the two nodes.    

PS-247 has a more extensive root system than other St. Augustinegrasses when grown under aquaculture conditions. PS-247 had twice the number of roots and nearly twice the total root length of the other varieties. This information, given in table 3, can be used to distinguish PS-247 from other tested grasses.

                  TABLE 3                                                          ______________________________________                                                 Total.sup.5       Average                                                      Root     Total    Root                                                 Selection-                                                                             Lgth.    Root     Lgth.  Longest                                                                               Water                                  Variety (cm)     Number   (cm)   Root   Use(cm)                                ______________________________________                                         PS-247(A)                                                                              551.3 ±                                                                              49.3 ±                                                                               11.2 ±                                                                             30.5 ±                                                                             5.8 ± 0.8                                   28.0     1.7      0.2    2.9                                           PS-247(B)                                                                              649.0 ±                                                                              57.3 ±                                                                               11.4 ±                                                                             30.8 ±                                                                             6.7 ± 0.3                                   85.3     8.2      0.8    3.2                                           Seville 201.7 ±                                                                              20.0 ±                                                                               10.0 ±                                                                             24.9 ±                                                                             5.3 ± 0.4                                   70.6     6.7      0.2    6.7                                           Raleigh 210.7 ±                                                                              23.7 ±                                                                                9.0 ±                                                                             22.5 ±                                                                             6.5 ± 1.4                                   14.6     2.0      1.1    1.1                                           Floratam                                                                               385.0 ±                                                                              27.7 ±                                                                               14.1 ±                                                                             41.1 ±                                                                             6.9 ± 0.4                                   55.7     5.4      1.2    6.4                                           Floratine                                                                              320.3 ±                                                                              25.0 ±                                                                               11.4 ±                                                                             30.8 ±                                                                             6.7 ± 0.3                                   91.2     8.2      0.8    3.2                                           L.S.D.(.05)                                                                            108.3    8.6      2.7    9.4    1.5                                    ______________________________________                                          .sup.5 All root measurements and water use measurements made under             aquaculture growth study in greenhouse.                                  

The purple stigma color and the light purple anther color of PS-247 along with the unreduced chromosome number of 18 allow this genotype to be easily distinguished from other commercially available St. Augustinegrasses. PS-247 is the only St. Augustine which has this particular combination. This information and comparisons with other cultivars is given in Table 4.

                  TABLE 4                                                          ______________________________________                                         Selection-                                                                              Stigma      Anther      Chromosome                                    Variety  Color       Color       Numbers.sup.6                                 ______________________________________                                         PS-247   Deep Purple Light Purple                                                                               18                                            Tex. Com.                                                                               White       Light Yellow                                                                               18                                            Seville  Light Purple                                                                               Light Yellow                                                                               18                                            Raleigh  White       Med. Yellow 18                                            Floratam Deep Purple Deep Yellow 27                                            Floratine                                                                               Light Purple                                                                               Deep Yellow 27                                            ______________________________________                                          .sup.6 Chromosome number determinations made on pollen mother cells.     

An electroporesis study carried out by Dr. James O. Anderson of Vari-Ident Laboratories suggest that PS-247 could be distinguished from Texas Comman, Raleigh, and Seville using various standard enzyme stains on a protein extract.

The rapid rate of cover and the outstanding stolon length of PS-247 can be used to identify this variety when compared to the other St. Augustinegrasses. These characteristics are considered very important in a vegetatively propagated species marketed through sod. This information which shows the lateral aggressiveness of PS-247, Raleigh and Floratam is summarized in Table 5.

                  TABLE 5                                                          ______________________________________                                         Selection-                                                                              Rate of Cover    Stolon Length(cm)                                    Variety  10/16.sup.7                                                                             12/2    3/28  10/16                                          ______________________________________                                         PS-247   4.0      7.0     8.7   57.4                                           Tex. Com.                                                                               3.7      6.3     8.7   42.3                                           Seville  3.0      5.3     7.7   34.7                                           Raleigh  4.3      7.3     9.0   50.6                                           Floratam 3.7      7.3     8.7   43.8                                           Floratine                                                                               2.3      4.6     8.7   31.1                                           L.S.D.(.05)                                                                             1.6      2.5     1.0   18.0                                           ______________________________________                                          .sup.7 Rate of Cover is rated with 1 = least cover and 9 = 100 percent         cover.                                                                   

Turfgrass quality and color, although not definitive in these early tests, indicate that PS-247 can be identified based on improved performance under test conditions. PS-247 was selected over 400 genotypes because of outstanding performance. Turfgrass quality and color ratings for 1984 and 1985 are given in Table 6.

                  TABLE 6                                                          ______________________________________                                         Selection-                                                                              Turfgrass Quality.sup.8                                                                        Turfgrass Color.sup.9                                 Variety  10/16   12/12   3/29  10/16 12/12 3/28                                ______________________________________                                         PS-247   6.3     6.0     6.3   7.0   7.3   7.0                                 Tex. Com.                                                                               6.7     6.0     6.3   6.7   7.0   6.0                                 Seville  6.3     4.7     6.0   7.0   6.7   7.0                                 Raleigh  6.3     5.7     6.7   6.7   7.3   7.7                                 Floratam 5.7     6.0     5.3   7.0   7.3   6.7                                 Floratine                                                                               5.7     4.7     4.3   6.7   6.7   6.3                                 L.S.D.(.05)                                                                             1.1     2.1     1.7   0.6   0.8   1.6                                 ______________________________________                                          .sup.8 Turfgrass Quality is rated with 1 = very poor quality and 9 =           outstanding turfgrass quality.                                                 .sup.9 Turfgrass Color is rated as 1 = straw brown color and 9 = very dar      green color.                                                             

PS-247 has shown strong levels of disease resistance in initial tests and observations. It has had low gray leafspot (Pircularia grisea) readings in bare soil establishment tests where innoculum sources are at their highest. This variety has not shown any downy mildew (Sclerophthora macrospora) in the greenhouse when surrounded by infected plants, and has been shown to be St. Augustine decline virus resistant in laboratory tests at Texas A & M. This information and comparisons to other plants are given in Table 7.

                  TABLE 7                                                          ______________________________________                                                                    Downy                                               Selection-                                                                              Gray Leafspot     Mildew   S.A.D                                      Variety  10/16.sup.10                                                                            12/12    3/28  12/10  Virus.sup.11                           ______________________________________                                         PS-247   1.3      1.0      1.0   1.0    R                                      Tex. Comm.                                                                              1.3      1.0      1.0   1.0    S                                      Seville  3.0      1.7      2.7   4.0    R                                      Raleigh  1.7      1.0      1.0   1.0    R                                      Floratam 1.7      2.7      1.7   1.0    R                                      Floratine                                                                               2.3      1.3      1.7   1.0    S                                      L.S.D.(.05)                                                                             1.0      1.0      1.0   --     --                                     ______________________________________                                          .sup.10 Disease ratings are made with 1 = no infection to 9 = 100 percent      infection.                                                                     .sup.11 St. Augustine Decline Virus Resistance(R) and Susceptibility(S)        were determined by Dr. Robert W. Toler, Texas A & M University.           

I claim:
 1. A St. Augustinegrass, substantially as herein described and illustrated, characterized by its rapid lateral spread and root length and numbers. 